This system (Koch's Pastulates) cannot be used to identify a disease cause if:

-You cannot grow microbes into a artifical culture.

-pathogen will only cause disease in humans.

(H.I.V) can't use humans as test animals.

-Disease cycle takes to long

-Can't observe symptoms objectively.

Epidemiology?

Study of how disease 'move" in a population.

Endemic?

Present in population at all times (low level).

Ex: common cold, bladder infection

Epidemic?

Increased for confined period of time, in a confined area (in one particular area)

Ex: Swine Flu

Pandemic?

Worldwide epidemic

Ex: AIDS

Tracking diseases?

-Concentrate on "Notifiable diseases."

-Can have significant impact on public health.

-Reported to:

County Public Health then to

State Public Health to

Center of Disease Control (CDC) to

World Health Organization (WHO)

Non-specific response?

The bodies rapid response:

-Fever, chilis, aches, redness, swelling, rash, diarrhea.

Specific response?

Response that take llonger, but necessary for a cure:

-Antibody production

-Killing of infected host cells

Targeted to a specific microbe

Long-term protection

-Memory cells that are produced "remember" that microbe and when exposed agian the memory cells "kick in" and rapidly eliminate microbes.

Memory cells?

Make protection by vaccine possible. Vaccine microbial afntigen is given to the patient for the immune response make memory cells.

Immune system components?

Fluid is removed from the blood vessel to tissues (carring nutrients) to lymph vessels (drainage system) to lymph nodes (containg phagocytic wbc's) filtering debris and mivrobe and fluid then back to the blood.

Swollen lymph nodes?

Mostly due to an increase in the number of phagocytic wbc's(responding to infection)

Leukocytes (white blood cells)?

All are formed from blood cell steam cells.

T-lymphocytes?

Mature in the thymus

B-lymphocytes?

Mature in the bursa tissue (bone marrow)

Antibodies?

Y shaped proteins each tip can attach to a antigen

Aggulutination?

Enhances phagocytosis and reduce number of infectious units to be dealt with by trapping the bacteria.

Neutralization (no longer a treat)?

Blocks adhesion of bacteria and viruses to mucosa by coating with antibodies.

OR

Blocks active site of toxin (molecule).

Activation of Complement?

Only kills the bacteria (cell lysis). Complement binds with antibodies to help lysin the bacteria.

Inflammation?

Disruption of cell by complement/reactive protein attracts (antibodies) phagocytic and other defensive immune system cells.

ID50?

Infectious dose- number of microbes needed to establish infection in 50% of the population.